“Distributed Development and Fun Features of Special Relativity”
is the subject of this month’s Estes Valley Astronomical Society (EVAS) meeting. EVAS in
conjunction with The Estes Park Memorial Observatory is offering a free public open
house/star night on Saturday, June 24th, at 7 PM. The goal of EVAS is to promote amateur
astronomy and education in the Estes Valley.

This illustrated presentation for the general public will begin by looking at how the Theory of
Special Relativity was developed by scientists over a period of about 50 years, culminating
with Einstein’s famous publication in 1905. Historians still debate the contributions of various
individuals. In any case, Special Relativity represents a remarkable advancement in our
understanding of space and time, particularly when high (relativistic) velocities are involved.

By considering how measures of length, mass, and time depend on velocities, we can
understand why certain particles strike the Earth whereas they could not do so without
relativistic effects. In addition, we will examine relativistic implications for forms of matter like
“tardyons” (e.g., people), “luxons” (light photons), and “tachyons” Hypothetical tachyons travel
faster than the speed of light, have imaginary mass, and violate cause and effect relationships.
(Scientists don’t like them!) Whereas photons must have zero rest mass, it can be shown that
they still possess energy and momentum. After discussing different time measurements
involved with space travel, the aging of astronauts, and the Twin Paradox, we will consider
something more practical like how to adjust our watch if we change time zones and the
adjustment stem is broken (assuming we have a good spaceship at our disposal).

Our speaker is Dr. Gordon MacAlpine, a retired astronomer, physicist, and a member of the
EVAS club. He received a BA in physics from Earlham College and a Ph.D. in astronomy from
the University of Wisconsin. After a stint at the Institute for Advanced Study in Princeton, NJ,
he joined the faculty at the University of Michigan where he was a Professor of Astronomy until
2000. Then he accepted the Zilker Distinguished Professor of Physics chair at Trinity
University in San Antonio, TX, where he continued teaching astronomy, physics, and
environmental science until his retirement in 2012.

The observatory is just north of the high school at 1600 Manford Ave. Park in the teacher’s
parking lot adjacent to the observatory. The doors will open at 7:00pm and the meeting will
start at 7:30pm. The presentation, including a question-and-answer period, lasts about an
hour. After the presentation, weather permitting, we will look through the telescope at various
celestial objects. Information about the meeting can be found on the observatory website at:
www.AngelsAbove.Org